Prevalence of refractive error in school children of Karachi

To find out the prevalence of refractive error and the eye morbidity in the school children and the associated factors.

One thousand students were selected from different schools of Karachi adopting two stage sampling technique. List of schools was obtained from Board of Secondary Education and 20 schools were randomly selected from the list in the five districts of Karachi during that period. Fifty students from each school were then selected adopting simple random technique.

A total of 1000 children from 20 schools were selected. However 940 were examined. The prevalence of refractive error was 8.9%. Mean age of the students was 9.49 +/- 2.5. Dominant ethnic group was Urdu speaking. Only 10.9% children were ever checked for their ophthalmic examination. Refractive error was associated with female sex but no association was found with class, age, ethnicity, parental education and other risk factors. About 1% students were color blind. Lack of association with increasing class may be due to poor educational training at Public sector schools.

An increased prevalence of refractive error was found in this study. There is a need of periodical eye examination, preferably while entering and leaving the school.